Stiffener member and bow riser assembly and archery bow comprised thereof

ABSTRACT

A riser and an archery bow including the riser are described herein. The riser includes a stiffener member to reduce deflection or bending of the riser. In an example, the stiffener member is integrated into the frame of the riser. In another example, the stiffener member is coupled to an external surface of the riser.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a non-provisional of, and claims the benefit and priority of, U.S. Provisional Patent Application No. 62/011,611, filed on Jun. 13, 2014. The entire contents of such application are hereby incorporated by reference.

BACKGROUND

Archery bows and, in particular, compound bows utilize many parts to transfer energy to a projectile. In conventional designs, these parts include a bowstring, flexible limbs, and a cam assembly (including cables and pulleys). The archery bow also includes a bow riser, which integrates these parts together into a structure that provides mechanical advantage to an archer that draws back on the bowstring to prepare for a shot. The mechanical advantage stores significant amounts of energy to deliver the projectile at higher speeds.

This energy generates significant loading on the bow riser during operation of the archery bow. It is important, therefore, that the bow riser exhibit mechanical properties (e.g., stiffness) to reduce deflection of the bow riser to ensure repeatable and accurate delivery of the projectile. These properties can also prevent riser fatigue and other operational problems that can cause failure of the bow riser, thereby leading to potential hazardous operational issues.

Attempts to strengthen the bow riser can lead to several disadvantages. Adding materials to the riser by making it thicker or wider causes relatively high weight. Heavy risers can result in fatigue experienced by archers. Heavy risers, leading to high weight bows, can also hinder archers in aiming due the difficulty in holding the high weight bows.

Also, when an archer purchases a bow and later learns that it has inadequate riser strength, the bow may be unusable. This can result in complete loss in use of such a bow even though only the riser portion of the bow is inadequate.

The foregoing background describes some, but not necessarily all, of the problems, disadvantages and shortcomings related to bow risers.

SUMMARY

The subject matter disclosed herein relates to archery equipment with particular discussion about construction of a bow riser for use on an archery bow. This disclosure suggests improvements that can impart strength to the bow riser. In one embodiment, the archery bow incorporates stiffening members that couple with the riser. Examples of the stiffening members can have mechanical properties that enhance, for example, the stiffness of the bow riser without interfering with overall operation of the archery bow to launch a projectile.

In an embodiment, a riser includes a front configured to face in a forward direction toward a target and a rear located opposite of the front, the rear configured to face in a rearward direction away from the target. The riser also includes a first stiffener mount and a second stiffener mount. The riser assembly additionally includes a riser stiffener. The riser stiffener includes a first coupler configured to couple to the first stiffener mount and a second coupler configured to couple to the second stiffener mount. When the riser stiffener is coupled to the riser before the riser is subject to a bow draw force, the riser stiffener exerts a riser force acting in the forward direction on the riser. Additionally, when the riser is subject to the bow draw force the riser force at least partially counteracts the bow draw force to reduce bending in the riser.

In another embodiment, a riser assembly for a bow includes a riser including a riser frame. The riser frame includes a front surface configured to face toward a target, a back surface configured to face away from the target in a rearward direction, and at least two side surfaces. The front, back, and side surfaces define a longitudinal opening. The riser assembly additionally includes a stiffener positioned within the longitudinal opening, the stiffener being coupled to the riser frame.

In a further embodiment, an archery bow includes a riser. The riser includes a riser section having a first end, a second end, and a riser body extending between the first and second ends. The riser body includes a front configured to face toward a target and a rear configured to face in a rearward direction away from the target. The archery bow also includes a stiffener member configured to be coupled to the riser section. The stiffener member is configured to reduce bending of the riser in the rearward direction.

Additional features and advantages of the present disclosure are described in, and will be apparent from, the following Brief Description of the Drawings and Detailed Description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of an embodiment of a stiffener assembly for use on an archery bow.

FIG. 2 is a schematic diagram of an embodiment of a stiffener assembly for use on an archery bow.

FIG. 3 is an illustration of an embodiment of a stiffener assembly for use on an archery bow.

FIG. 4 is a side view illustration of an embodiment of a stiffener assembly.

FIG. 5 is a side isometric illustration of an embodiment of a stiffener assembly.

FIG. 6 is a front isometric illustration of an embodiment of a stiffener assembly.

FIG. 7 is a rear isometric illustration of an embodiment of a stiffener assembly.

FIG. 8A is a side view illustration of an embodiment of a stiffener assembly.

FIG. 8B is an exploded side view illustration of an embodiment of a stiffener assembly.

FIG. 9 is a side isometric illustration of an embodiment of a stiffener assembly.

FIG. 10 is a rear view illustration of an embodiment of a stiffener assembly.

FIG. 11 is a side view illustration of an embodiment of a stiffener assembly.

FIG. 12 is a partial side isometric illustration of an embodiment of a stiffener assembly.

FIG. 13 is a partial side isometric illustration of an embodiment of a stiffener assembly.

FIG. 14 is a partial rear isometric illustration of an embodiment of a stiffener assembly.

DETAILED DESCRIPTION

FIG. 1 is a schematic of an archery bow 106 including stiffener members 108. In this embodiment, a stiffener assembly 100 includes one or more stiffener members (e.g., a first stiffener member 102 and a second stiffener member 104). The stiffener assembly 100 is part of an archery bow 106. The bow 106 has a riser 108 and a grasp, grip, or handle 110. The riser 108 has a front 112 facing toward a shooting target and a back 114 facing in a rearward direction 115 opposite of the shooting target. The back 114 is positioned closer to an end user that readies the archery bow 106 in position to fire a projectile.

In an embodiment, the riser 108 additionally includes a first riser section or upper riser section 107 and a second riser section or lower riser section 109. While the riser 108 is described here as having two sections, it is to be understood that a riser can have additional sections. On either section 107, 109 of the riser 108, the archery bow 106 includes a limb element (e.g., a first limb element 116 and a second limb element 118) that supports a cam assembly 120. Examples of the cam assembly 120 can include one or more cam members (e.g., a first cam member 122 and a second cam member 124) that couple with the limb elements 116, 118. As also shown in FIG. 1, the archery bow 106 can include a bowstring assembly 126 with one or more bowstrings 128 that couple with the cam members 122, 124.

The stiffener assembly 100 is configured to prevent, minimize, reduce or decrease the rearward deflection or bending of the riser 108 during the archer's rearward draw of the archery bow 106. This configuration can couple the stiffener members 102, 104 with the riser 108 in positions that afford appropriate mechanical stiffness and/or other mechanical properties. During operation, the stiffener members 102, 104 counteract bending, flexing, torsion, and like forces that result from the archer's rearward draw on the bowstrings 128. The positions for the members 102, 104 may, for example, correspond to known weak points in the riser 108; weak points are often found proximate the handle, arrow shelf, and “sight” window, as well as other locations at which the configuration or construction of the riser 108 results in less than favorable material properties, such as material thickness, and/or geometry, such as chamfers, small radii, etc., that leave the riser 108 susceptible to failures. In one implementation, the stiffener assembly 100 operates to alleviate strain, as well as stresses and vibration, at these locations that can propagate through the riser 108, while maintaining certain cost, weight, and/or aesthetic properties to ease the use of the archery bow 106.

Construction of the stiffener members 102, 104 can facilitate the operative characteristics of the stiffener assembly 100. Construction of the stiffener members can include a body that comprises stiff, light-weight materials, for example, metals, such as aluminum, alloys, and composites, such as carbon fiber, although this disclosure contemplates the listing of materials to include any materials that may exhibit mechanical properties that comport with the mechanical advantages contemplated herein. The body of the stiffener member 102, 104 can utilize geometry that fits onto and/or fully and/or partially within the riser 108. For example, FIG. 1 illustrates one construction for the riser 108 that integrates at least part of one or more of the stiffener member 102, 104 with the riser 108.

In another example, FIG. 2 illustrates an embodiment in which the stiffener members 102, 104 are mounted to the back 114 of the riser 108. In another embodiment illustrated in FIG. 3, stiffening members 102, 104 are mounted to the front 112 of the riser 108. In an embodiment not illustrated, stiffening member 102 is mounted to the front 112, and stiffening member 104 is mounted to the back 114. While the stiffener members 102, 104 are illustrated here as both coupling to the front 112 of the riser or both coupling to the back 114 of the riser 108, it is to be understood that a riser 108 can include stiffener members coupled to the front 112 and/or the back 114 of the riser 108. Additionally, a riser 108 can include a stiffener 102, 104 integrated with the riser 108 and/or a stiffener member 102, 104 coupled to the riser 108.

FIGS. 4-6 illustrate an embodiment of a stiffener assembly 200 in a first mounting configuration. The Figures illustrate a first section 207 of the riser frame 208. This mounting configuration integrates the stiffener insert 204 into the structure of the archery bow 206. The stiffener assembly 200 includes a riser frame 208 within the first riser section 207. The frame 208 defines a longitudinal cavity 230. The cavity 230 extends longitudinally or vertically between the first end or upper riser end 209 of the first riser section 207 and the second end or lower riser end 211 of the first riser section 207 of the riser 208. The stiffener insert 204 is disposed inside of the longitudinal cavity 230. Any suitable method of coupling the stiffener insert 204 to the riser 208 is contemplated herein. In one example, the archery bow 206 can include one or more fasteners (e.g., screws, bolts, etc.) that penetrate the stiffener insert 204 and the riser section 207 to couple the stiffener insert 204 to the riser section 207. Construction of the archery bow 206 may also utilize adhesives and/or bonding agents, either alone or in conjunction with the fasteners, to secure the stiffener insert 204 in position in the riser section 207. In another example, the stiffener insert 204 and the riser section 207 can be monolithic or unitary.

Referring to FIG. 5, in an embodiment, the stiffener insert 204 includes a matrix or array of cross beams or cross supports 212. The frame 207 and the cross supports 212 collectively define a plurality of inner openings 210 extending laterally through the stiffener insert 204. The inner openings 210 can be positioned along the length of the stiffener insert 204. By including the plurality of inner openings 210 in the stiffener insert 204, the stiffener insert 204 can prevent, inhibit or reduce deflection of the riser 208 without significantly increasing the weight of the riser section 207 and, ultimately, the bow in which the riser section 207 is incorporated. While FIGS. 4-6 illustrate a single section 207 of the riser 208 and a stiffener insert 204 integrated therein, it is to be understood that the riser 208 further includes at least a second section to which an additional stiffener member can be coupled and/or integrated.

FIGS. 7-9 illustrate an embodiment of part of a bow 301 having a stiffener assembly 300 in a second mounting configuration. In this embodiment, the stiffener element or stiffener member 304 is coupled to an exterior part of the riser section 308, such as the back 314 of the riser section 308. As illustrated, the back 314 faces in the rearward direction 115 opposite of the shooting direction. In one example, the stiffener element 304 has a first end 332 and a second end 334. The riser section 308 includes a stiffener interface with features that couple with the stiffener element or member 304. These features may include one or more mounting members (e.g., a first mounting member 336 and a second mounting member 338) that are configured to receive at least part of the stiffener member 304, namely, the first end 332 and the second end 334, respectively. For example, referring to FIG. 9, the riser section 308 can include at least one stiffener mount portion 310, and the stiffener member 304 can include at least one stiffener coupler 312. For example, the stiffener member 304 can include a stiffener coupler 312 at each end 332, 334. The stiffener mount portion(s) 310 is configured to receive the stiffener coupler(s) 312 to couple the stiffener member 304 to the riser. In an embodiment, the stiffener mount portions 310 are shoulder portions of the riser section 308. Each such shoulder portion defines a hole or passage configured to receive a pin, shaft member or other fastener. The fastener enables a user to couple the stiffening member 304 to the bow 301.

In an example, the mounting members 332, 334 may be integral (or monolithic) with the structure of the riser section 308. However, this disclosure contemplates configurations in which the mounting members 332, 334 are separate pieces that assemble to the riser 308. As noted above, the archery bow 306 may include fasteners and/or adhesives and/or bonding agents to secure the stiffener member 304 in position at the mounting members 336, 338. In another example, the stiffener member 304 is integral with the structure of the riser section 308.

In an example illustrated in FIG. 8A, when the stiffener member 304 is coupled to the riser section 308, a longitudinal gap 314 extends between the stiffener member 304 and the riser section 308. The longitudinal gap 314 reduces weight of the riser section 308 when coupled to the stiffening member 304. In an example, the gap 314 extends longitudinally between the coupling points 336, 338 of the stiffener member 304 and the riser section 308.

In an embodiment illustrated in FIG. 8B, the riser section 308 defines a distance D1 between mount point 336 and mount point 338. The stiffening member 304 defines a distance D2 between coupler end 332 and coupler end 334. In such embodiment, D2 is greater than D1. As a result, the stiffening member 304 applies a forward force to the riser section 308 acting in the forward direction 303. To install the stiffener member 304, the stiffener member 304, the user slightly bends the riser section 308 in the forward direction 303 and then couples the stiffener member 304 to the riser section 308. Thus, installation of the stiffener member 304 pre-loads the riser section 308, or exerts a force on the riser section 308 in the forward direction 303, so that the riser section 308 is under tension and the stiffener member 304 is under compression. In an embodiment, the stiffener member 304 includes a spring element or spring characteristic so as to bias the riser in the forward direction 303. Such forward force of the stiffening member 304 counteracts the archer's backward draw force. Consequently, such forward force reduces the backward bending or displacement of the riser section 308 during use of the bow 301.

FIGS. 10-11 illustrate another embodiment of a stiffener assembly 400. This embodiment includes stiffener members 402, 404 disposed proximate, respectively, the sight window region 412 and the grip region 414 of the bow riser 408. In one example, the stiffener members 402, 404 are configured as generally thin plates, with features that permit the plates to secure to the bow riser.

FIGS. 12-13 further illustrate the sight window region 412. In this embodiment, the sight window 412 includes an upper surface 416, a lower surface 418, and a side surface 420. Additionally, the sight window 412 can include an opening opposite the side surface 420. The stiffener member 402 is positioned such that a first end 422 of the stiffener member 402 is coupled to the upper surface 416 of the sight window 412 and the second end 424 of the stiffener member 402 is coupled to the lower surface 418 of the sight window 412. The stiffener member 402 is coupled to the sight window 412 by stiffener couplers 426, 428 such that the stiffener member 402 extends along the sight window 412 and covers the opening opposite the side surface 420.

FIG. 14 further illustrates the grip region 414. In this embodiment, the stiffener member 404 extends along the grip region. A first end 430 of the stiffener member 404 is coupled, via a stiffener coupler(s) 434, to a first end 438 of the grip region 414 and a second end 432 of the stiffener member 404 is coupled, via a stiffener coupler(s) 436, to a second end 440 of the grip region 414. The stiffener members 402, 404 are coupled to the sight window region 412 and/or the grip region 414 to prevent deflection of the riser 408 without interfering with operation of the sight window region 412 and the grip region 414.

As described above, implementations of the various embodiments can also serve to “preload” the bow riser. These implementations may, for example, leverage the mechanical stiffness and/or other mechanical properties of the stiffener members to influence the bow riser in a particular configuration and/or orientation, e.g., a slight twist, bend, etc. The influence may allow the bow riser to be tuned to suit a set of operative characteristics for the end user.

It should be appreciated that the stiffening members, when configured to be removeably attached to the bow riser, can provide opportunities for the use of bows that have riser weaknesses. For example, an archer may install one or more stiffening members as after-market accessories to improve the strength of a previously purchased bow.

Additional embodiments include any one of the embodiments described above, where one or more of its components, functionalities or structures is interchanged with, replaced by or augmented by one or more of the components, functionalities or structures of a different embodiment described above.

It should be understood that various changes and modifications to the embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present disclosure and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.

Although several embodiments of the disclosure have been disclosed in the foregoing specification, it is understood by those skilled in the art that many modifications and other embodiments of the disclosure will come to mind to which the disclosure pertains, having the benefit of the teaching presented in the foregoing description and associated drawings. It is thus understood that the disclosure is not limited to the specific embodiments disclosed herein above, and that many modifications and other embodiments are intended to be included within the scope of the appended claims. Moreover, although specific terms are employed herein, as well as in the claims which follow, they are used only in a generic and descriptive sense, and not for the purposes of limiting the present disclosure, nor the claims which follow. 

The following is claimed:
 1. A riser assembly for a bow, the riser assembly comprising: a riser comprising: (a) a front configured to face in a forward direction toward a target; (b) a rear located opposite of the front, the rear configured to face in a rearward direction away from the target; (c) a first stiffener mount; and (d) a second stiffener mount; and a riser stiffener comprising: (a) a first coupler configured to couple to the first stiffener mount; and (b) a second coupler configured to couple to the second stiffener mount; wherein when the riser stiffener is coupled to the riser before the riser is subject to a bow draw force, the riser stiffener exerts a riser force acting in the forward direction on the riser, and wherein, when the riser is subject to the bow draw force, the riser force at least partially counteracts the bow draw force to reduce bending in the riser.
 2. The riser of claim 1, wherein the riser comprises at least two riser stiffeners coupled to the riser, a first riser stiffener coupled to a first section of the riser and a second riser stiffener coupled to a second section of the riser.
 3. The riser of claim 1, wherein the riser stiffener is coupled to the riser such that a gap extends longitudinally between the rear of the riser and the riser stiffener.
 4. The riser of claim 1, wherein the riser further comprises a sight window positioned in the riser.
 5. The riser of claim 4, wherein the sight window comprises an opening in the riser, the sight window comprising an upper surface, a lower surface, and at least one side surface.
 6. The riser of claim 5, wherein the upper surface and the lower surface each comprise a stiffener mount and wherein the riser stiffener comprises a first and second stiffener coupler configured to couple the riser stiffener to the riser along the sight window.
 7. The riser of claim 1, wherein the riser comprises a plurality of riser sections and a grip section between the riser sections, wherein the riser stiffener is coupled to the riser such that the riser stiffener extends along at least part of the grip section.
 8. The riser of claim 1, wherein the riser stiffener is configured to minimize deflection of the riser.
 9. The riser of claim 1, wherein the riser stiffener is configured to be removeably coupled to the riser.
 10. A riser assembly for a bow, the riser assembly comprising: a riser comprising a riser frame, the riser frame comprising: a front surface configured to face toward a target, a back surface configured to face away from the target in a rearward direction, and at least two side surfaces, the front, back, and side surfaces defining a longitudinal opening; and a stiffener positioned within the longitudinal opening, the stiffener being coupled to the riser frame.
 11. The riser of claim 10, wherein the stiffener defines a plurality of cross supports defining a plurality of inner stiffener openings, and wherein the cross supports and inner stiffener openings are configured to reduce deflection of the riser in the rearward direction while reducing weight increase caused by inclusion of the stiffener in the riser frame.
 12. The riser of claim 10, wherein the stiffener is a stiffener insert configured to be removeably disposed in the longitudinal opening.
 13. The riser of claim 10, wherein the riser and the stiffener are unitary.
 14. An archery bow comprising: a riser comprising a riser section, the riser section comprising: (a) a first end; (b) a second end; and (c) a riser body extending between the first and second ends, the riser body comprising a front configured to face toward a target and a rear configured to face in a rearward direction way from the target and a stiffener member configured to be coupled to the riser section, wherein the stiffener member is configured to reduce bending of the riser in the rearward direction.
 15. The archery bow of claim 14, wherein the riser and the stiffener member are unitary.
 16. The archery bow of claim 14, the riser further comprising at least one stiffener coupler configured to removeably couple the stiffener member to the riser section.
 17. The archery bow of claim 14, wherein the a riser section comprises: (a) a front configured to face toward the target; (b) a rear located opposite of the front, the rear configured to face in the rearward direction; (c) the first end comprising a rearward extension extending in the rearward direction, the rearward extension comprising a first stiffener mount; and (d) the second end comprising a second stiffener mount; and the stiffener member comprising: (a) a first coupler configured to couple to the first stiffener mount; and (b) a second coupler configured to couple to the second stiffener mount; wherein, when the riser is subject to a bow draw force acting in the rearward direction: (a) the first end of the riser undergoes a rearward force, and (b) the first coupler of the stiffener member counteracts the rearward force to reduce bending in the riser.
 18. The archery bow of claim 14, wherein the stiffener member is coupled to the riser such that a gap extends longitudinally between the stiffener member and the riser.
 19. The archery bow of claim 14, wherein the riser section comprises a frame comprising: a first end and a second end; and a front surface configured to face toward the target, a back surface configured to face away from the target in the rearward direction, and at least two side surfaces, the front, back, and side surfaces defining a longitudinal opening; and the stiffener member positioned within the longitudinal opening, the stiffener member being coupled to the riser frame.
 20. The archery bow of claim 14, wherein the stiffener member comprises a stiffness that is greater than a stiffness of the riser of the archery bow.
 21. The archery bow of claim 14, wherein the stiffener member comprises carbon fiber.
 22. The archery bow of claim 14, wherein when the stiffener member is coupled to the riser, the stiffener member exerts a force acting in the forward direction on the riser. 